Integrated Physical Unclonable Function (Puf) with Combined Sensor and Display

Abstract

The present invention relates to a device ( 100, 200, 300 ) and a method for creating challenge-response pairs. A basic idea of the present invention is to create a challenge in the form of light emitted onto a light scattering element ( 103, 203 ), which light will be scattered in the light scattering element and detected as a response to the challenge by light detecting elements ( 105, 205 ). The light scattering element comprises a transmissive material which contains randomly distributed light scattering particles ( 104, 204 ), which scatter incident light such that a random speckle pattern is created and spread over the light detecting elements. This random pattern is detected by the light detecting elements, and is known as the response to the challenge (i.e. the light) that was supplied to the light scattering element. Hence, a challenge-response pair is created. Further, picture elements ( 109, 209 ) are included in the device in order to enable modification of the challenge created by a light source ( 101, 201 ) and supplied to the light scattering element. By activating picture elements and thereby modifying the challenge, one will also modify the response that corresponds to the modified challenge.

1 . A device for creating challenge-response pairs comprising:
 a light source;   a light scattering element;   a plurality of picture elements; and   a plurality of light detecting elements;   wherein the light source is arranged to create a challenge by illuminating the light scattering element,   the light scattering element is arranged to scatter incident light on the light detecting elements,   at least one of the picture elements is arranged to be activated to modify the challenge by reflecting incident light such that the reflected light illuminates the light scattering element, and   the light detecting elements are arranged to create a response to the modified challenge by detecting the light scattered on them.   
   
   
       2 . The device according to  claim 1 , further comprising a chip for integrating the light source, the light scattering element, the picture elements and the light detecting elements. 
   
   
       3 . The device according to  claim 2 , wherein the chip is a CMOS technology integrated circuit. 
   
   
       4 . The device according to  claim 1 , wherein the picture elements are interspersed with the light detecting elements. 
   
   
       5 . The device according to  claim 1 , wherein the picture elements are arranged in a group which is physically separated from the light detecting elements. 
   
   
       6 . The device according to  claim 1 , further comprising a light coupling element for coupling a light beam of the light source into the light scattering element. 
   
   
       7 . The device according to  claim 1 , wherein the light scattering element scatters light on the picture elements ( 109 ). 
   
   
       8 . The device according to  claim 1 , wherein light of the light source falls directly on the picture elements. 
   
   
       9 . The device according to  claim 1 , wherein the picture elements and light detecting elements are arranged in the same plane. 
   
   
       10 . The device according to  claim 1 , further comprising a liquid crystal layer arranged on the picture elements. 
   
   
       11 . The device according to  claim 1 , wherein the picture elements include MEMS picture elements. 
   
   
       12 . A method of creating challenge-response pairs comprising:
 creating a challenge by illuminating a light scattering elements;   activating at least one of a plurality of picture elements to modify the challenge by reflecting light incident on said at least one picture element such that the reflected light illuminates the light scattering element; and   creating a response to the modified challenge by detecting the light scattered by the light scattering element.   
   
   
       13 . The method of  claim 12 , wherein creating a response further comprises detecting the scattered light with light detecting elements. 
   
   
       14 . The method according to  claim 12 , wherein creating a challenge further comprises coupling a light beam of a light source into the light scattering element. 
   
   
       15 . The method according to  claim 12 , further comprising scattering light of the light source on the picture elements. 
   
   
       16 . (canceled) 
   
   
       17 . (canceled) 
   
   
       18 . (canceled) 
   
   
       19 . (canceled) 
   
   
       20 . A computer program embodied on a computer-readable medium comprising a computer-executable code for causing the acts comprising:
 creating a challenge by illuminating a light scattering element;   activating at least one of a plurality of picture elements to modify the challenge by reflecting light incident on said at least one picture element such that the reflected light, illuminates the light scattering element; and creating a response to the modified challenge by detecting the light scattered by the light scattering element.